As is well known in the gas turbine engine art, the durability of engine components is of paramount importance and, obviously the longer an engine component endures the longer an engine can perform without the costly shutdown of the airplane necessitated by the repair or replacement of such components. It is therefore a constant concern to develop components that can withstand the hostile environment to which they are subjected. As to be expected, one area that has been particularly troublesome is in the combustor and particularly where the fuel nozzles are attached to the combustor liner. The fuel nozzle guide and seal that supports the fuel nozzle at the front end of the annular combustor has been subjected to extraordinary thermal stresses and has heretofore been a maintenance problem. Because of these problems, noted above, the life of these components were not as long as one would like them to be.
To this end, we have found that we can obtain a longer life of the nozzle guide and seal elements than have heretofore been obtainable by fabricating the seal and heat shield integral with the fuel nozzle guide and defining an annular U-shaped element in cross section that traps the combustor liner for relative movement between the fuel nozzle and combustor. One leg of the U-shaped element serves as a heat shield, while the other serves to support the fuel nozzle guide to the liner. Cooling air holes are formed in the base of the U and so as to be routed to continuously cool the heat shield and nozzle. Tabs arranged on the inner surface of the heat shield prevent it from collapsing and blocking flow.
Discretely mounted openings between the nozzle and nozzle guide serves to eliminate any void or recess in the area adjacent the nozzle and nozzle support facing the combustion zone to prevent it from acting as a flame holder and creating localized hot spots.